The present invention relates to a standard reference for calibrating a scanning electron microscope, a fabrication method therefor, and a scanning electron microscope using it.
In recent years, miniaturization is proceeding in the semiconductor device increasingly, which requires higher-precision dimensional control. Accordingly, in the field of fabrication of the semiconductor device, dimensional control using an electron-beam length measurement apparatus based on the scanning electron microscope is being practiced. Measurement precision of this dimensional control is determined by precision of magnification calibration of the scanning electron microscope.
However, when measurement at higher magnifications is performed in response to the miniaturization of the semiconductor device, a pattern of a standard reference with which magnification calibration is performed is required to have a micro-precision feature comparable to the semiconductor pattern or higher because the field of view of the scanning electron microscope has a narrow area. To respond to this requirement, as a calibration reference having the micro-precision feature with a pitch size of 100 nm or less, a super lattice sample as shown in Misumi et al. “2006 The Japan Society of Precision Engineering (JSPE) Spring Meeting, Technical Digest,” pp. 1091 is proposed.